Validation of a flash glucose monitoring system in outpatient diabetic cats

BACKGROUND: Interstitial glucose (IG) concentration measurement using a flash glucose monitoring system (FGMS) is a noninvasive, affordable, and informative method to regulate patients with diabetes mellitus (DM) but has not been fully validated in outpatient cats with DM. OBJECTIVES: To further validate the FreeStyle Libre FGMS in outpatient diabetic cats. ANIMALS: Eight client‐owned cats with DM. METHODS: Prospective observational validation study. Tissue glue was used to attach the sensor to the cat. Lin's concordance correlation coefficient (ρ (c)) was used to compare IG concentrations measured by the FGMS to blood glucose concentrations measured using an automated biochemistry analyzer (ABA) and point‐of‐care glucometer (POCG). RESULTS: Data from 15 sensor placements in 8 cats were analyzed. Paired IG and ABA glucose concentrations (139 samples) had excellent correlation (ρ (c) = 0.96) as did IG and POCG glucose concentrations (142 samples, ρ (c) = 0.92). Sensor failure or displacement were recorded for 12/15 (80%) sensor placements. Median time of sensor activity was 7 days (range, 2‐13 days). CONCLUSIONS AND CLINICAL IMPORTANCE: In outpatient cats with DM, the FGMS‐measured IG concentration correlated well with ABA‐measured blood glucose concentration, but a high rate of sensor failures was observed.